The primary objective of Sentinel-3 is marine observation, the mission studies sea-surface topography, sea and land surface temperature, ocean and land colour. Composed of two satellites, the mission's primary instrument is a Radar Altimeter, but the polar-orbiting satellites carry multiple instruments, including optical imagers as well. The first Sentinel-3 satellite was launched in 2016.

The objective of Sentinel-2 is Land monitoring, and the mission is composed of two polar-orbiting satellites providing high-resolution optical imagery. Vegetation, soil and water cover, inland waterways and coastal areas are among the monitoring objectives. Sentinel-2 also provides disaster monitoring for emergency services. The first Sentinel-2 satellite was launched on 23 June 2015.

With the objectives of Land and Ocean monitoring, Sentinel-1 is composed of two polar-orbiting satellites operating day and night, and performs Radar imaging, enabling them to acquire imagery regardless of the weather. The first Sentinel-1 satellite was launched on a Soyuz rocket from Europe's Spaceport in French Guiana on 03 April 2014.

A constellation of three satellites, the Swarm mission aims to provide the best survey of the Earth's geomagnetic field and its temporal evolution, as well as discovering new insights into our world's interior and climate.

The Proba-V mission provides multispectral images to study the evolution of the vegetation cover on a daily and global basis. The 'V' stands for Vegetation. This mission is extending the data set of the long-established Vegetation instrument, flown as a secondary payload aboard France's SPOT-4 and SPOT-5 satellites launched in 1998 and 2002 respectively.

ESA's Earth Explorer CryoSat is Europe's first ice mission. The aim
of the mission is to determine variations in the thickness of the
Earth's continental ice sheets and marine ice cover. Its primary
objective is to test the prediction that Arctic sea ice is thinning
due to global warming. In addition, it was important to discover
the extent to which the Antarctic and Greenland ice sheets are
contributing global sea level rise.

ESA's Soil Moisture and Ocean Salinity (SMOS) mission has been
designed to observe soil moisture over the Earth's landmasses and
salinity over the oceans. Soil moisture data are urgently required
for hydrological studies and data on ocean salinity are vital for
improving our understanding of ocean circulation patterns.

As part of ESA's Living Planet programme, the Gravity field and
steady-state Ocean Circulation Explorer (GOCE) is the first of a
series of Earth Explorer satellites in orbit, designed to provide
information for understanding critical Earth system variables. It
has been developed to bring about a whole new level of
understanding of one of the Earth's most fundamental forces of
nature - the gravity field.

Envisat (ENVIronmental SATellite) is an advanced polar-orbiting Earth observation satellite which provided measurements of the atmosphere, ocean, land, and ice over 10 years of operations. The Envisat satellite carried an ambitious and innovative payload that ensured the continuity of the data measurements from the ERS satellites. The archive of data received from the satellite supports Earth science research and aids in the long-term monitoring of environmental and climactic changes. Contact with Envisat was lost on 08 April 2012, and the mission was officially ended on 09 May 2012.

The PRoject for On-Board Autonomy (Proba) is a technology demonstration mission of the European Space Agency, The objectives of Proba are: in-orbit demonstration and evaluation of new hardware and software spacecraft technologies, onboard operational autonomy, and trial and demonstration of Earth observation and space environment instruments.

The European Remote Sensing satellite, ERS-1, launched in 1991, was
ESA's first sun-synchronous polar orbiting remote sensing mission,
operated until March 2000. ERS-1 carried a comprehensive payload
including an imaging Synthetic Aperture Radar (SAR), a radar
altimeter and other powerful instruments to measure ocean surface
temperature and winds at sea. ERS-2, which overlapped with ERS-1,
was launched in 1995 with an additional sensor for atmospheric
ozone research. ERS-2 far exceeded its nominal lifetime and was
retired on 04 July 2011.